How to add a char/int to an char array in C?

Question

How can I add \'.\' to the char Array := \"Hello World\" in C, so I get a char Array: \"Hello World.\" The Question seems simple but I\'m struggling.

Tried the follo

Answer 1

In C/C++ a string is an array of char terminated with a NULL byte ('\0');

1. Your string str has not been initialized.
2. You must concatenate strings and you are trying to concatenate a single char (without the null byte so it's not a string) to a string.

The code should look like this:

char str[1024] = "Hello World"; //this will add all characters and a NULL byte to the array
char tmp[2] = "."; //this is a string with the dot 
strcat(str, tmp);  //here you concatenate the two strings

Note that you can assign a string literal to an array only during its declaration.
For example the following code is not permitted:

char str[1024];
str = "Hello World"; //FORBIDDEN

and should be replaced with

char str[1024];
strcpy(str, "Hello World"); //here you copy "Hello World" inside the src array